1. Field of the Invention
This invention relates to an electrical connector for electrically interconnecting parallel multiconductor main and branch cables together.
2. Description of the Prior Art
A control unit and a plurality of input and output units are interconnected together by cables for the purpose of factory automation, for example, so that signals are transmitted between the control unit and each of the input and output units. The number of cabling equal to the number of the input and output units is required in this regard. Accordingly, as the number of the input and output units is increased, cabling becomes more troublesome and a space for cabling becomes larger.
In view of the above problem, the prior art has recently provided for signal transmission systems with saved cabling wherein the minimum number of signal lines is employed for the signal transmission between the control unit and the input and output units. FIG. 38 illustrates one of such signal transmission systems. One end of a flat four-wire main cable 2 is connected to a control unit 1. Electrical connectors 4 are provided for electrically connecting one ends of branch cables 3 to the main cable 2 respectively. Address units 5 are connected to the other ends of the branch cables 3 respectively. A plurality of input or output units 6 or 7 are connected to each address unit 5.
When data is delivered from the control unit 1 to each output unit 7, the control unit 1 delivers to the address unit 5 a data signal representative of output data and address data of the output unit 7 to which the output data is to be supplied. The address unit 5 specifies the output unit 7 to which the output data is to be supplied, on the basis of the address data of the data signal delivered thereto. The address unit 5 then delivers the output data to the specified output unit 7. On the other hand, when inputting data from each input unit 6, each address unit 5 delivers a data signal with address data to the control unit 1. The control unit 1 specifies the input unit 6 from which the data has been input, on the basis of the address data of the data signal supplied thereto from the address unit 5.
The main and branch cables 2, 3 are interconnected by the connector 4 in the following manner. The main cable 2 is cut off at a desired branch point. Both cut ends of the main cable 2 are connected to a connecting member and then, another connecting member is attached to the end of the branch cable 3. These two connecting members are interconnected together by a further another connecting member. Accordingly, the main cable 2 needs to be cut off at the number of times corresponding to the number of the branch cables 3, and three connecting members are required at each branch point. Consequently, cabling becomes troublesome and the number of the connectors connecting between the main and branch cables is increased with the result of increase in the cost for the factory automation.
To solve the above-described drawback, Japanese Unexamined Patent Application Publication No. 3-171572 discloses an electrical connector for interconnecting flat multiconductor cables.. The disclosed connector electrically connects between an intermediate portion of a flat multiconductor main cable 2 and a branch cable 3, as shown in FIGS. 39 to 41. The intermediate portion of the main cable 2 is placed on the upper face of a housing 8. In this state, an upper pressing member 9 is pressed from upward and a lower pressing member 10 is pressed from below. Consequently, the main and branch cables 2, 3 are press fitted into concave portions of connecting members 11 projecting from the upper and bottom faces of the housing 8, thereby being electrically connected to the connecting members 11, respectively. The main and branch cables 2, 3 are thus connected electrically together.
In the above-described conventional construction, however, the main cable 2 needs to be positioned on the housing 8 and then, the upper pressing member 9 needs to be pressed against the housing 8 when the branch of the main cable 2 is attached to the housing 8. The housing 8 sometimes slips out of the branch position of the main cable 2 while the upper pressing member 9 is being pressed. This reduces the working efficiency for connection and reliability in the connection.